The present invention relates to a sensor assembly which may be utilized to detect objects at a location spaced from the sensor assembly.
A known sensor assembly has a light source or emitter from which light is transmitted to an object spaced from the sensor assembly. The light is reflected from the object back through a second lens to a detector.
Users of known sensor assemblies have tried to gain access to the interior of the sensor assemblies by engaging wrenching flats on electrical connectors for the sensor assemblies. This can result in unauthorized tampering with the sensor assemblies in a manner which is detrimental to the operation of the sensor assemblies.
The lenses in a sensor assembly should be easy to accurately position in the sensor assembly. In addition, the lenses in a sensor assembly should not become loose during use of the sensor assembly. It is also important to have the light source and light detector accurately positioned relative to each other and to the lenses.
From a commercial standpoint, it is necessary to minimize the cost of a sensor assembly. It is also desirable to make the sensor assembly compact so that it can be easily positioned in many different environments. There should be minimal reflection of light from components of a sensor assembly. The lenses in a sensor assembly should be protected from the environment in which the sensor assembly is utilized so that the operating qualities of the sensor assembly do not deteriorate with the passage of time.
The present invention relates to a new and improved sensor assembly. The sensor assembly includes a light source and a lens which directs light from the light source to a remote object. Light reflected from the remote object is transmitted through another lens to a light detector.
The lenses may advantageously be mounted on a lens carrier. The lens carrier is disposed in a housing. The lenses are advantageously connected with the lens carrier by a plurality of releasable connectors. The connectors may be disposed in engagement with the rim portions of the lenses and press the lenses into recesses formed in the lens carrier. The connectors may be of the snap-in type.
The sensor assembly may advantageously include a connector assembly which connects the sensor assembly with an electrical conductor. This tamper resistant electrical connector assembly may include a body portion and a flange portion. The flange portion may be movable to engage a recess in the sensor housing and retain the electrical connector assembly against movement along a central axis of body portion of the connector assembly. In order to resist unauthorized access to the interior of the sensor assembly, a retainer may engage the flange portion of the electrical connector assembly and hold the flange portion against movement out of engagement with the recess.
The light source and/or the light detector may be movable relative to a circuit board to adjust the distance at which light from the light source is reflected from an object back to the detector. The circuit board may be connected with the lens carrier. A black coating may advantageously be provided on a side of the circuit board facing toward the lenses.
The sensor assembly may include one or more of a plurality of features of the present invention. It should be understood that although the features may advantageously be used in combination with each other, the features may also be used separately.